At a hearing in December, Miss Rivett's son Neil Berriman was given permission to intervene in the case.

But speaking after today's ruling, Mr Berriman, 49, said: "I think he's (Lucan) dead. It is fantastic and I am very pleased for him (Bingham)."

Murdered Nanny Sandra Rivett (Image: LNS)

Even though Lord Lucan was officially declared dead by the High Court in 1999, there have been reported sightings in Australia, Ireland, Africa and New Zealand, and even claims that he fled to India and lived life as a hippy called "Jungly Barry".

Lord Bingham argued that the 1999 declaration had not proved death "for all purposes" and the new Presumption of Death Act allowed for a "more complete process".

On the night of the peer's disappearance, the nanny's attacker also turned on Lord Bingham's mother, Lady Lucan, beating her severely before she managed to escape and raise the alarm at a nearby pub.

Lord Lucan's car was found abandoned and soaked in blood in Newhaven, East Sussex, and an inquest jury declared him the killer a year later.